Cylinder lock and u-shaped key and method of forming same

ABSTRACT

A cylinder type lock is designed to receive a U-shaped key having tumbler manipulating grooves formed in facing surfaces of its essentially parallel side portions. The key is formed by providing V-shaped slots in a key blank to bound the inwardly facing surfaces of the side portions and a connecting bridge portion, cutting the manipulating grooves in the inwardly facing surfaces of the side portions in a predetermined relationship to the slots and then folding the side portions relative to the bridge portion.

United States Patent 1191 Stackhouse Aug. 28, 1973 [54] CYLINDER LOCK AND U-SHAPED KEY AND 2,039,126 4/1936 Svoboda 70/46 METHOD OF FORMING SAME 2,620,649 12/1952 Bernardo 3,035,433 5/1962 Testa Inventor: Wells Smklwun, Ashville. 3,058,336 10/1962 Tocchetto 70/364 R [73] Assignee: American Locker Co., Inc.,

Jamestown, Primary Examiner-Robert L. Wolfe Attorney-John B. Bean et al. [22] Filed: June 26, 1972 21 Appl. No.: 266,141 57] ABSTRACT A cylinder type lock is designed to receive a U-shaped 52 US. Cl. 70/364 R, 70/377, 70/401, key having tumbler manipulating grooves formed in 70/407 facing surfaces of its essentially parallel side portions. [51] Int. Cl. E05c 19/02, EOSc 29/10 h k y is formed by providing V-shaped slots in a key [58] Field 61 Search 70/362, 364 R, 364 A, blank to bound the inwardly facing surfaces the side 70/367, 373, 375, 377, 401, 402, 405-409, portions and a connecting bridge P cutting the 419, 421; 29/76 C manipulating grooves in the inwardly facing surfaces of the side portions in a predetermined relationship to the [56] R f CM slots and then folding the side portions relative to the UNITED STATES PATENTS bndge 2,023,207 12/ I935 Olson..- 70/409 X 13 Claims, 9 Drawing Figures Patented Aug. 28, 1973 Nkm km 2 Sheets-Sheet 1 Patented Aug. 28, 1973 2 Sheets-Sheet 2 CYLINDER LOCK AND U-SIIAPED KEY AND METHOD OF FORMING SAME BACKGROUND OF THE INVENTION It has heretofore been proposed to provide cylinder type locks with two rows of tumblers with a view to rendering the lock more difficult to pick, as evidenced by US. Pat. No. 2,620,649. In this type of prior lock construction, tumbler manipulating surfaces are formed along the free edges of facing side walls of a generally U-shaped key.

While cylinder locks having two rows of tumblers are more difficult to pick than comparable single row locks, they still suffer from the same disadvantage, that is, their keys are relatively simple to duplicate.

SUMMARY OF THE INVENTION The present invention is directed towards an improved cylinder lock designed to accommodate a U- shaped key having tumbler manipulating portions or receiving grooves formed on facing inner surfaces of the key side walls. A key formed in accordance with the present invention is substantially impossible to duplicate unless one possesses specialized key forming equipment.

Moreover, the cylinder lock of the present invention incorporates additional novel features including plate type tumblers, wherein the tumblers of each row are arranged to straddle one of the key side walls and operably engage with the tumbler manipulating grooves of the other or opposite key side wall; and an improved bearing assembly for journaling the plug within the cylinder.

DRAWINGS The nature and mode of the present invention will now be more fully described in the following detailed description taken with the accompanying drawings wherein:

FIG. 1 is an exploded perspective view illustrating the lock construction of the present invention;

FIG. 2 is a top plan view of the plug with adjacent parts shown in section;

FIG. 3 is a bottom plan view of the plug with adjacent parts shown in section;

FIG. 4 is a sectional view taken generally along line 44 in FIG. 2;

' FIG. 5 is a sectional view taken generally along line 5-5 in FIG. 2;

FIG. 6 is a plan view of a key blank employed in the practice of the present'invention; I

FIG. 7 is an end view of the blank shown in FIG. 6;

FIG. 8 is a side view of a formed key; and

FIG. 9 is a sectional view taken generally along line 9-9 in FIG. 8.

' DETAILED DESCRIPTION Reference is now made more particularly to FIG. 1, wherein a cylindrical lock and a U-shaped key formed in accordance with the present invention are generally designated as 10 and 12, respectively.

To facilitate understanding of the present invention key 12 will now be briefly described with reference to FIGS. 1, 8 and 9 as generally including a pair of parallel side walls or portions 14 and 15 and a bridging wall or portion 16, which is formed integrally with side walls 14 and 15. In a preferred construction, the facing or inner surfaces and 15a of the side walls are each formed with tumbler manipulating surface portions in the form of lengthwiseextending undulating grooves 18 and 19, respectively. A more detailed description of key 12 and its method of fabrication will hereinafter be given with particular reference to FIGS. 6 and 7.

As in conventional lock constructions, cylinder lock 10 generally includes a cylinder 24, which serves to mount the lock within an opening provided in a cabinet, drawer or like face plate, which is designated as 26 only in FIGS. 2 and 3; and a key plug 28, which is rotatably supported by cylinder 24 and serves to carry a cam plate or member 30 for movement between locking and unlocking positions under the control of key 12. In the arrangement shown, a C-ring 32, which is snap-fitted into a cylinder groove 34, cooperates with an enlarged flange 36 formed adjacent the front end of the cylinder 24 to retain the cylinder fixed relative to face plate 26; and cam plate 30 is fixed to the rear end of key plug 28 by an assembly including screw 38 and washers 40. The rear end of the key plug is shaped to define a reduced diameter cylindrical portion 37a and a squared end 37b.

In accordance with the present, invention, key plug 28 is formed with a key slot 42, which is of a generally rectangular cross-sectional configuration and extends rearwardly through the front end of the key plug, and two rows of mirror image, generally L-shaped tumbler receiving openings 44 and 45, which are positioned within the mid portion of the key plug to extend transversely of and 'in communication with key slot 42. As

will be apparent from viewing FIGS. 1 through 5, receiving openings 44 and 45 are staggered in a direction lengthwise of the key plug and serve to slideably accommodate plate like tumblers generally designated at 46 and 47, respectively. When key plug 28 is in its locked position illustrated in the drawings, the upper and lower end portions of openings 44 and 45, which are designated as 44a, 45a and 44b, 45b, respectively, are disposed in registry with a pair of upper slots 48 and 50 and a single lower slot 52, which are arranged to extend lengthwise of the cylindrical inner surface 53 of cylinder 24.

Tumblers 46 and 47 are best shown in FIGS. 4 and 5 as being of mirror image, generally J-shaped configuration including main or upper leg portions 46a and 47a, which are received within upper end portions 440 and 450; base or connecting portions 46b and 47b, which are received within lower end portions44b and 45b; and operating leg portions 46cand 47c, which terminate in laterally projecting lugs 46d and 47d dimensioned to be received in key manipulating grooves 19 and 18, respectively. As will be apparent from viewing FIGS. 4 and 5, tumblers 46 and 47 are retained in assembled relationship within key plug 28 by means of a tumbler retainer bar 54, which additionally serves to define the upper surface of key slot 42.

Again referring to FIGS. 4 and 5, it will be understood that when the proper key is inserted into key plug 28 tumblers 46 and 47 are manipulated thereby to move vertically into the positions illustrated, wherein the upper ends of tumbler legs 46a and 47a and connecting portions 46b and 47b and disposed essentially flush with the outer surface of the key plug to free the key plug for unlocking rotation within the cylinder. As will be apparent, the force of gravity and/or spring devices, not shown, normally serves to retain tumbler connecting portions 46b and 47b in locking engagement within lower slot 52 when no key is inserted and slots 48 and 50 accommodate for vertical movements of the upper leg portions 460 and 47a occasioned by the insertion of the key into the key plug.

In the preferred construction illustrated, tumblers 46 and 47 cooperate with key slot 42 to define an inverted essentially U-shaped passageway arranged in alignment with an inverted U-shaped opening 56 formed in a face plate 58. Face Plate 58 is retained within a slot recess 60 formed in the front face of key plug front end flange 62 by a plug cap 64. Cap 64 is formed with an opening 66 to afford access to opening 56 and is suitably affixed to key plug flange 62, as by a crimping operation. As will be apparent, the key plug opening defined by key slot 42 and tumblers 46 and 47 is dimensioned to slideably accommodate a U-shaped key of desired size and to insure precise positioning of manipulating grooves 18 and 19 relative to the upper and lower surfaces of such opening and thus relative to the vertical positions projecting legs 46d and 47d must assume to permit unlocking movements of the key plug.

Again referring to FIGS. 1-3, it will be seen that lock additionally includes a novel arrangement for supporting key plug 28 for rotation within cylinder 24. In this connection, it will be seen that flange 62, the cylindrical mid portion and portion 37a of key plug 28 are supported in a non-contacting relationship relative to enlarged front end opening 70, inner surface 53 and inwardly extending rear annular flange 72 of cylinder 28, respectively, by a front, flat washer type bearing ring 74 and a rear, split U-shaped bearing part 76. Rearwardly directed axial thrust on the key plug is carried to cylinder flange 36 by bearing ring 74, whereas forwardly directed axial thrust on the key plug is carried to cylinder flange 72 by bearing part 76.

Reference is now made particularly to FIGS. 6 and 7, wherein key 12 is shown as being formed from a flat metal key blank, which is lengthwise divided by a pair of parallel essentially V-shaped grooves 80 and 81. Grooves 80 and 81 cooperate to define an inner surface 16a of bridge portion 16 and cooperate with opposite marginal edges 82 and 83 of the blank to define inwardly facing surfaces 14a and a, as well as facilitate accurate, controlled folding of the key blank in the manner to be described.

In the preferred method of forming key 12, pregrooved key blanks are stocked and, as required, a blank is cut to form manipulating grooves 18 and 19 corresponding to the predetermined tumbler unlocking configuration of a given lock. For a given size key, grooves 80 and 81 of all blanks are spaced a given distance apart and relative to marginal edges 82 and 83. Thus, in cutting manipulating grooves 18 and 19, grooves 80 and 81 and/or marginal edges 82 and 83 may be used as an accurate cutting reference. Incidental to the cutting of grooves 18 and 19, their key insertion or open ends are flared as at 180 and 19a in order to facilitate manipulation of the tumblers as the key is progressively inserted into the lock for which the key is designed.

After grooves 18 and 19 have been cut, the blank is arranged within a suitable jig, shown for purposes of reference in phantom line in FIG. 7, and folded along grooves 80 and 81 to produce the final U-shaped key configuration shown in FIGS. 1, 8 and 9. If desired, the ends of side walls 14 and 15, which are to be gripped for the purpose of manipulating the key may be serrated, as illustrated, or enclosed by a cover device, not shown, to enhance gripping of the key and/or to provide for a desired decorative appearance.

The deforming jig would include a constraining or pressure member 90 arranged to bear against or constrain the whole of inner surface 160 intermediate grooves and 81, and a pair of folding members 92 and 93, which are suitably mounted for pivotal movements in opposite directions toward member about a pair of parallel axes 94 and 95, respectively. It will be understood that axes 94 and 95 are disposed in a parallel spaced relationship relative to bridging portion outer surface 16b and lie within a pair of parallel planes lengthwise bisecting grooves 80 and 81, respectively.

By deforming the key blank in this manner, stretch deformation of the metal forming the blank is limited to the outer comers 96 and 97 of the formed key opposite grooves 80 and 81, and the adjacent edges of surfaces 14a, 15a and 160 are accurately brought together in right angular relationship. As a result, the size and configuration of surfaces 14a, 15a and 16a, as well as the thicknesses of side walls 14 and 15 and bridging portion 16, are not effected by the blank deforming operation. Thus, the distance between grooves 18 and 19 and marginal edges 82 and 83 remains unchanged, whereas the distance between the grooves 18 and 19 and outwardly facing surface 16b corresponds to the thickness of bridge portion 16 and the original distance between such groovesand their associated grooves 80 and 81. These distances are extremely critical for properly maintaining vertical manipulation of the tumblers, since in the construction illustrated in FIGS. 4 and 5, surface 16b and marginal edges 82 and 83 will slideably engage with the upper and lower surfaces of key slot 42, respectively.

Accordingly, extremely close tolerances may be maintained for both the key and the lock, which renders it substantially impossible to duplicate a given key without having access to appropriate key blanks and a properly designed forming jig. Moreover, the close spacing between surfaces and 15a, which is on the order of about one-sixteenth inch, renders it extremely difficult or impossible to trace grooves 18 and 19 of a formed key without telltale destruction thereof or to cut such grooves in another key having a pre-formed U-shaped configuration.

I claim:

1. In a cylinder lock, the combination comprising:

a generally U-shaped key having a pair of facing side portion and a bridge portion connecting said side portions, at least one of said side portions having tumble manipulating surfaces on a surface thereof facing the other of said side portion;

a key plug having a key slot extending through one end thereof for receiving said key and at least one row of spaced tumbler receiving openings extending transversely of said key slot and in communication therewith;

tumblers positioned within said tumbler receiving openings, said tumblers having portions thereof arranged to be received between said side portions of said key for engagement with said tumbler manipulating surfaces when said key is inserted into said key slot, and

a casing for rotatably receiving said plug and having tumbler receiving openings therein arranged to register with said tumbler receiving openings of said plug.

2. A lock according to claim 1, wherein said manipulating surfaces of said one side portion is defined by an undulating groove extending lengthwise of said side portions.

3. A lock according to claim 1, wherein manipulating surfaces are formed on each of said side portions, said key plug is formed with two rows of tumbler receiving openings, and the openings of one of said rows are staggered relative to the openings of the other of said rows.

4. A lock according to claim 3, wherein said manipulating surfaces are defined by undulating grooves extending lengthwise of said side portions.

5. A lock according to claim 3, wherein each said tumbler is in the form of a plate lying within a plane disposed transversely of said key receiving slot, and the tumblers received within one of said rows of openings are notched to straddle one of said key side portions and the tumblers received within the other of said rows of openings are notched to straddle the other of said key side portions.

6. A lock according to claim 5, wherein said manipulating surfaces of each said side portion is defined by an undulating groove extending lengthwise thereof, and said tumblers engage with an undulating groove of a side portion other than that which they straddle.

7. A lock according to claim 1, wherein manipulating surfaces are formed on each of said side portions, said key plug is formed with two rows of tumbler receiving openings, and the openings of one of said rows are staggered relative to the openings of the other of said rows, said plug slot is of rectangular cross-sectional configuration, said plug carries a face plate adjacent its one end, said face plate having a U-shaped key receiving opening therethrough, and said tumblers cooperate with said plug slot to define a generally U-shpaed key receiving passageway arranged in alignment with said face plate when said key is inserted through said face plate into said plug slot for lock opening engagement with said tumblers.

8. A lock according to claim 1, wherein said key plug is supported for rotation in spaced relationship concentrically inwardly of said casing by front and rear bearing devices, said front and rear bearing devices transferring rearwardly and forwardly directed axial thrust, respectfully, from said key plug to said cylinder.

9. A U-shaped key for a cylinder lock comprising in combination:

a pair of side portions having parallel facing surfaces, at least one of said facing surfaces being formed with surface portions for manipulating tumblers of a cylinder lock; and

a bridge portion formed integrally with and connecting said side portions, said bridge portion having an inwardly facing surface thereof disposed at right angles to said facing surfaces of said. side portions.

10. A key according to claim 9, wherein each of said facing surfaces is formed with surface portions for manipulating tumblers of a cylinder lock and said surface portions are defined by undulating grooves extending lengthwise of said side portions.

11. A key according to claim 10, wherein said side and bridge portions are formed by deforming a single flat metal key blank into a U-shaped configuration, and characterized in that the metal of said blank forming said facing surfaces and said inner surface of said bridge portion is unstressed by deforming of said blank.

12. A method of forming a key of U-shaped configuration having facing side portions and a bridge portion connecting said side portions for use in combination with a key actuated cylindrical lock of the reciprocating tumbler type, wherein key engaging heads of tumblers are arranged to engage with tumbler operating surface portions formed on the facing surface of at least one of said facing side portions, which includes the steps of:

providing a key blank formed with a pair of parallel essentially V-shaped grooves in one surface thereof, said grooves cooperating with each other to bound an inner surface of said bridge portion and cooperating with spaced marginal edges of said blank to bound facing surfaces of said side portions; forming said operating surface portions in said one surface intermediate one of said grooves and a corresponding one of said marginal edges of said blank; and constraining substantially the whole of said inner surface of said bridge member while folding said blank along said grooves to produce said Ushaped key configuration while preventing stress deformation of said inner surface and said facing surfaces, whereby the distance between said operating surface portions and said associated marginal edge remains essentially unchanged as said blank is folded to form said key and the distance between said operating surface portions and an outwardly facing surface of said bridge portion of the formed key corresponds to the thickness of said bridge portion and the distance between said operating surface portions and said one groove of the unfolded blank. 13. A method according to claim 12, wherein said operating surface portions are formed in each of said facing surfaces and are in the form of undulating grooves extending lengthwise of said facing surfaces, and said blank is folded by placing a pair of folding members in engagement with outwardly facing surfaces of said side portions and pivoting said folding members about associated ones of a pair of axes, said axes being arranged in an equally spaced parallel relationship to said outwardly facing of said bridge member and lying within a pair of parallel planes lengthwise bisecting said V-shaped grooves.

Patent No. 3 7- 4 422 Dated August 28, 1973 WELLS F. STACKHOUSE Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 52, "portion" should read portions line 55, "portion" should read portions Column 5,.

line 4, "is" should read are" line 24, "is" should read are H line 39, after "plate", insert opening Column 6, line .5'5, after "facing", insert surface Signed and sealed this 22nd day of January 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. Attesting Officer RENE D. TEGTMEYER Acting Commissioner of Patents 

1. In a cylinder lock, the combination comprising: a generally U-shaped key having a pair of facing side portion and a bridge portion connecting said side portions, at least one of said side portions having tumble manipulating surfaces on a surface thereof facing the other of said side portion; a key plug having a key slot extending through one end thereof for receiving said key and at least one row of spaced tumbler receiving openings extending transversely of said key slot and in communication therewith; tumblers positioned within said tumbler receiving openings, said tumblers having portions thereof arranged to be received between said side portions of said key for engagement with said tumbler manipulating surfaces when said key is inserted into said key slot, and a casing for rotatably receiving said plug and having tumbler receiving openings therein arranged to register with said tumbler receiving openings of said plug.
 2. A lock according to claim 1, wherein said manipulating surfaces of said one side portion is defined by an undulating groove extending lengthwise of said side portions.
 3. A lock according to claim 1, wherein manipulating surfaces are formed on each of said side portions, said key plug is formed with two rows of tumbler receiving openings, and the openings of one of said rows are staggered relative to the openings of the other of said rows.
 4. A lock according to claim 3, wherein said manipulating surfaces are defined by undulating grooves extending lengthwise of said side portions.
 5. A lock according to claim 3, wherein each said tumbler is in the form of a plate lying within a plane disposed transversely of said key receiving slot, and the tumblers received within one of said rows of openings are notched to straddle one of said key side portions and the tumblers received within the other of said rows of openings are notched to straddle the other of said key side portions.
 6. A lock according to claim 5, wherein said manipulating surfaces of each said side portion is defined by an undulating groove extending lengthwise thereof, and said tumblers engage with an undulating groove of a side portion other than that which they straddlE.
 7. A lock according to claim 1, wherein manipulating surfaces are formed on each of said side portions, said key plug is formed with two rows of tumbler receiving openings, and the openings of one of said rows are staggered relative to the openings of the other of said rows, said plug slot is of rectangular cross-sectional configuration, said plug carries a face plate adjacent its one end, said face plate having a U-shaped key receiving opening therethrough, and said tumblers cooperate with said plug slot to define a generally U-shpaed key receiving passageway arranged in alignment with said face plate when said key is inserted through said face plate into said plug slot for lock opening engagement with said tumblers.
 8. A lock according to claim 1, wherein said key plug is supported for rotation in spaced relationship concentrically inwardly of said casing by front and rear bearing devices, said front and rear bearing devices transferring rearwardly and forwardly directed axial thrust, respectfully, from said key plug to said cylinder.
 9. A U-shaped key for a cylinder lock comprising in combination: a pair of side portions having parallel facing surfaces, at least one of said facing surfaces being formed with surface portions for manipulating tumblers of a cylinder lock; and a bridge portion formed integrally with and connecting said side portions, said bridge portion having an inwardly facing surface thereof disposed at right angles to said facing surfaces of said side portions.
 10. A key according to claim 9, wherein each of said facing surfaces is formed with surface portions for manipulating tumblers of a cylinder lock and said surface portions are defined by undulating grooves extending lengthwise of said side portions.
 11. A key according to claim 10, wherein said side and bridge portions are formed by deforming a single flat metal key blank into a U-shaped configuration, and characterized in that the metal of said blank forming said facing surfaces and said inner surface of said bridge portion is unstressed by deforming of said blank.
 12. A method of forming a key of U-shaped configuration having facing side portions and a bridge portion connecting said side portions for use in combination with a key actuated cylindrical lock of the reciprocating tumbler type, wherein key engaging heads of tumblers are arranged to engage with tumbler operating surface portions formed on the facing surface of at least one of said facing side portions, which includes the steps of: providing a key blank formed with a pair of parallel essentially V-shaped grooves in one surface thereof, said grooves cooperating with each other to bound an inner surface of said bridge portion and cooperating with spaced marginal edges of said blank to bound facing surfaces of said side portions; forming said operating surface portions in said one surface intermediate one of said grooves and a corresponding one of said marginal edges of said blank; and constraining substantially the whole of said inner surface of said bridge member while folding said blank along said grooves to produce said U-shaped key configuration while preventing stress deformation of said inner surface and said facing surfaces, whereby the distance between said operating surface portions and said associated marginal edge remains essentially unchanged as said blank is folded to form said key and the distance between said operating surface portions and an outwardly facing surface of said bridge portion of the formed key corresponds to the thickness of said bridge portion and the distance between said operating surface portions and said one groove of the unfolded blank.
 13. A method according to claim 12, wherein said operating surface portions are formed in each of said facing surfaces and are in the form of undulating grooves extending lengthwise of said facing surfaces, and said blank is folded by placing a pair of folding members in engagement with outwardly facing surfaces of said side portions and pivoting said folding members about associated ones of a pair of axes, said axes being arranged in an equally spaced parallel relationship to said outwardly facing of said bridge member and lying within a pair of parallel planes lengthwise bisecting said V-shaped grooves. 